Integrated circuit surface layer with adhesion-functional group

ABSTRACT

Embodiments of the present disclosure describe an integrated circuit and associated fabrication techniques and configurations, which may include forming on at least one of a metal layer or a polymer layer of an integrated circuit die a surface layer that includes an adhesion-functional group, and applying to the surface layer a next layer to adhere to the surface layer with the adhesion-functional group. In embodiments wherein the at least one of the metal layer or the polymer layer is a polymer layer, forming the surface layer may include copolymerizing on the polymer layer a polar monomer that includes the adhesion-functional group. In embodiments wherein the at least one of the metal layer or the polymer layer is a metal layer, forming the surface layer may include forming on the metal layer a self-assembled monolayer that includes amine group terminations. Other embodiments may be described and/or claimed.

TECHNICAL FIELD

Embodiments of the present disclosure generally relate to the field ofintegrated circuits, and more particularly, to adhesion-receptivesurfaces for integrated circuit die layers and associated techniques andconfigurations.

BACKGROUND

Currently, integrated circuit dies include successive layers, such aspolymer/polymer, polymer/metal or polymer/silica, between which theremay be low adhesion. Techniques to improve adhesion betweenpolymer/polymer and polymer/silica layers may include plasma orultra-violet (UV) treatment of the surfaces to enhance the surface areaor surface energy. Techniques to improve adhesion between polymer and anunderlying metal layer may include etching of the metal, but etching maydegrade electrical performance or patterning.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be readily understood by the following detaileddescription in conjunction with the accompanying drawings. To facilitatethis description, like reference numerals designate like structuralelements. Embodiments are illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings.

FIG. 1 schematically illustrates a cross-section view of an exampleintegrated circuit (IC) die, in accordance with some embodiments.

FIG. 2 schematically illustrates a flow diagram for a method offabricating an IC, in accordance with some embodiments.

FIG. 3 schematically illustrates a cross-section view of another exampleIC die, in accordance with some embodiments.

FIG. 4 schematically illustrates a flow diagram for another method offabricating an IC, in accordance with some embodiments.

FIG. 5 schematically illustrates a flow diagram for a method of forminga self-assembled monolayer (SAM) on a metal layer of a die, inaccordance with some embodiments.

FIG. 6 schematically illustrates a computing device incorporating someaspects of embodiments described herein, in accordance with someembodiments.

DETAILED DESCRIPTION

Embodiments of the present disclosure describe an integrated circuit andassociated fabrication techniques and configurations, which may includeforming on at least one of a metal layer or a polymer layer of anintegrated circuit die a surface layer that includes anadhesion-functional group, and applying to the surface layer a nextlayer to adhere to the surface layer with the adhesion-functional group.In embodiments wherein the at least one of the metal layer or thepolymer layer is a polymer layer, forming the surface layer may includecopolymerizing on the polymer layer a polar monomer that includes theadhesion-functional group. In embodiments wherein the at least one ofthe metal layer or the polymer layer is a metal layer, forming thesurface layer may include forming on the metal layer a self-assembledmonolayer that includes amine group terminations.

In the following detailed description, reference is made to theaccompanying drawings which form a part hereof, wherein like numeralsdesignate like parts throughout, and in which is shown by way ofillustration embodiments in which the subject matter of the presentdisclosure may be practiced. It is to be understood that otherembodiments may be utilized and structural or logical changes may bemade without departing from the scope of the present disclosure.Therefore, the following detailed description is not to be taken in alimiting sense, and the scope of embodiments is defined by the appendedclaims and their equivalents.

For the purposes of the present disclosure, the phrase “A and/or B”means (A), (B), or (A and B). For the purposes of the presentdisclosure, the phrase “A, B, and/or C” means (A), (B), (C), (A and B),(A and C), (B and C), or (A, B and C).

The description may use the phrases “in an embodiment,” or “inembodiments,” which may each refer to one or more of the same ordifferent embodiments. Furthermore, the terms “comprising,” “including,”“having,” and the like, as used with respect to embodiments of thepresent disclosure, are synonymous.

The term “coupled with,” along with its derivatives, may be used herein.“Coupled” may mean one or more of the following. “Coupled” may mean thattwo or more elements are in direct physical or electrical contact.However, “coupled” may also mean that two or more elements indirectlycontact each other, but yet still cooperate or interact with each other,and may mean that one or more other elements are coupled or connectedbetween the elements that are said to be coupled with each other.

In various embodiments, the phrase “a first layer formed on a secondlayer” may mean that the first layer is formed over the second layer,and at least a part of the first layer may be in direct contact (e.g.,direct physical and/or electrical contact) or indirect contact (e.g.,having one or more other layers between the first layer and the secondlayer) with at least a part of the second layer.

In various embodiments, the phrase “a first feature formed, deposited,or otherwise disposed on a second feature,” may mean that the firstfeature is formed, deposited, or disposed over the second feature, andat least a part of the first feature may be in direct contact (e.g.,direct physical and/or electrical contact) or indirect contact (e.g.,having one or more other features between the first feature and thesecond feature) with at least a part of the second feature.

FIG. 1 schematically illustrates a cross-section view of an exampleintegrated circuit (IC) die 100 with layers 102 and 104, in accordancewith some embodiments. The die 100 may represent a discrete product madeon a substrate of semiconductor material (e.g., silicon) usingsemiconductor fabrication techniques such as thin film deposition,lithography, etching, and the like used in connection with forming ICdevices. In embodiments, the die 100 may be, include, or be a part of aradio frequency (RF) die, a processor, memory, system-on-chip (SoC), orASIC, for example.

Layers 102 and 104 may be two of two or more layers that are included indie 100. In embodiments, layer 102 may be of or include a polymer andmay be referred to as polymer layer 102. Polymer layer 102 may be formedupon one or more die layers 106 (only one shown), which may include asemiconductor substrate. Layer 104 may be applied to die 100 afterpolymer layer 102 and may be formed of or include metal, silica orpolymer. An adhesion-receptive surface 108 may be formed between layers102 and 104 to enhance adhesion between them. The adhesion-receptivesurface 108 enhance adhesion between layers 102 and 104 withoutadversely affecting mechanical and/or electrical properties of the bulkof polymer layer 102.

In embodiments, a layer 110 may optionally be applied to die 100 afterlayer 104. Layer 104 and/or 110 may be incorporated onto die 100 or maybe an embedding or encapsulating material that embeds or encapsulatesdie 100 in or as part of an IC package or package assembly (not shown).

FIG. 2 schematically illustrates a flow diagram for a method 200 offabricating an IC, in accordance with some embodiments. The method 200may comport with the configuration of die 100 in FIG. 1, for example.

At 202, the method 200 may include dispensing on a polymer layer of adie a solution that includes a polar monomer and a photoinitiator. Inembodiments, the polymer layer may be polymer layer 102, and the polarmonomer may include an adhesion-functional group that functionalizesadhesion between the polymer layer and the next layer. In embodiments,the functional group may include an amine group if the next layerincludes or is of silica, a cyano group if the next layer includes or isof a metal such as copper (Cu), or a hydroxyl group if the next layerincludes or is of a polymer. Dispensing the solution on the polymerlayer may include applying the solution in liquid form, such as bydipping the die and the polymer layer into the solution. In otherembodiments, the polar monomer may include more than oneadhesion-functional group to functionalize adhesion between the polymerlayer and the next layer. In embodiments, the more than one functionalgroups may include an amine group and a cyano group if the next layerincludes or is of a metal such as copper, or may include an amine groupand a hydroxyl group if the next layer includes or is of silica.

At 204, the method 200 may include exposing the solution on the polymerlayer to light to form on the polymer layer an adhesion-receptivepolymer surface, which may also be referred to as a surface layer thatincludes an adhesion-functional group. In embodiments, the light may beultra-violet light that may graft copolymerize the polar monomer on thepolymer layer to form the adhesion-receptive polymer surface. Theadhesion-receptive polymer surface may correspond to adhesion-receptivesurface 108 of FIG. 1.

At 206, the method 200 may include applying a next layer to theadhesion-receptive polymer surface to affix the next layer to thepolymer layer. In embodiments, the next layer applied to theadhesion-receptive polymer surface may be formed of or include materialsthat may include metal, silica, or polymer. The next layer maycorrespond to layer 104 of FIG. 1. In embodiments, the next layer may beof or include silica if the functional group of the polar monomer at 202includes an amine group, the next layer may be of or include a metalsuch as copper (Cu) if the functional group of the polar monomer at 202includes a cyano group, or the next layer may be of or include a polymerif the functional group of the polar monomer at 202 includes or ahydroxyl group. In other embodiments, the next layer may be of orinclude a metal such as copper if the polar monomer includes more thanone adhesion-functional group, such as an amine group and a cyano group,and the next layer may be of or include silica if the polar monomerincludes more than one adhesion-functional group, such as an amine groupand a hydroxyl group.

The method 200 may provide to polymer layer 102 the adhesion-receptivesurface layer 108 without affecting properties of the bulk of polymerlayer 102. In embodiments, polymer layer 102 may be free fromadhesion-functional groups by which adhesion-receptive surface layer 108may functionalize adhesion between polymer layer 102 and the next layer104. Adhesion-functional groups included in the bulk of polymer layer102 may adversely affect mechanical and/or electrical properties ofpolymer layer 102, including any or all of high modulus, low CTE, lowdielectric loss, etc., which may adversely affect reliability of an IC.Polymer layer 102 may be free from adhesion-functional groups such thatadhesion-functional groups are completely or sufficiently absent fromthe bulk of polymer layer 102 that its mechanical and/or electricalproperties are substantially unchanged. In embodiments,adhesion-receptive surface layer 108 may include an adhesion-functionalgroup, and polymer layer 102 may be free from the adhesion-functionalgroup.

In embodiments, the adhesion-receptive polymer surface provided bymethod 200 may be very thin (40-50 nm) and uniform. The uniformity maysmooth out issues that may be observed after some wet or dry processtreatments. The adhesion-receptive polymer surface provided by method200 may also enable polymer surfaces with higher surface energy andwettability. In embodiments, polar functional groups (e.g., carboxylicacid, amides, alcohols, etc.) may be employed to improve surface energyand/or wettability without resorting to plasma or UV treatment. If usedfor a solder resist layer, for example, method 200 may resolve ordecrease solder resist surface transparency issues.

Die embedding in a polymer material may be employed in some IC packagesand package assemblies, including system-in-package technologies thatmay include more than one IC die. Delamination between an embedded ICdie and an encapsulating dielectric may be a serious reliability issue.Method 200 may improve wettability for subsequent polymers included inmold, underfill, or encapsulant materials. A polymer or dielectric maybe functionalized through graft polymerization with adhesion-functionalgroups, which may include amines or silanols, to bind embedding surfaceswith greater reliability.

FIG. 3 schematically illustrates a cross-section view of another exampleIC die 300 with layers 302 and 304, in accordance with some embodiments.The die 300 may represent a discrete product made on a substrate ofsemiconductor material (e.g., silicon) using semiconductor fabricationtechniques such as thin film deposition, lithography, etching, and thelike used in connection with forming IC devices. In embodiments, the die300 may be, include, or be a part of a radio frequency (RF) die, aprocessor, memory, system-on-chip (SoC), or ASIC, for example.

Layers 302 and 304 may be two of two or more layers that are included indie 300. In embodiments, layer 302 may be of or include a metal (e.g.,copper) and may be referred to as metal layer 302. Metal layer 302 maybe formed upon one or more die layers 306 (only one shown), which mayinclude a semiconductor substrate. Layer 304 may be applied to die 300after metal layer 302 and may be formed of or include polymer. Anadhesion-receptive surface 308 may be formed between layers 302 and 304to enhance adhesion between them. In embodiments, a layer 310 mayoptionally be applied to die 300 after layer 304. Layer 304 and/or 310may be incorporated onto die 300 or may be an embedding or encapsulatingmaterial that embeds or encapsulates die 300 in or as part of an ICpackage or package assembly (not shown).

FIG. 4 schematically illustrates a flow diagram for a method 400 offabricating an IC, in accordance with some embodiments. The method 400may comport with the configuration of die 300 in FIG. 3, for example.

At 402, the method 400 may include forming on a metal layer (e.g.,copper) of a die a self-assembled monolayer (SAM) that includes aminegroup terminations. The SAM may be referred to as a surface layer thatincludes an adhesion-functional group. In embodiments, the metal layermay be metal layer 302, and forming the SAM may include applying to themetal layer an ethanolic solution that includes an alkane thiol with aterminal amine group, as described in greater detail below. The aminegroup may be referred to as an adhesion-functional group thatfunctionalizes adhesion between the metal layer and the next layer.

At 404, the method 400 may include applying a dielectric layer on thesurface layer. In embodiments, the dielectric layer may include an epoxyresin.

At 406, the method 400 may include heat-treating the die to affix thedielectric layer to the metal layer. In embodiments, heat-treating mayarise by contact and elevated temperature of a rubber press or a steelpress, or by a final IC polymer cure, which may provide a more prolongedheat-treatment period.

SAMs are instances of molecular interactions that lead to supramolecularorder. In embodiments, alkanes having a head group with an affinity fora surface may assemble in a close-packed network (e.g., in order tomaximize van der Waals interactions). To promote adhesion with adielectric layer, a terminal amine group may provide a chemical moietyto bond to the layer with enhanced adhesion. In embodiments, adielectric layer may include an epoxy resin, which may include a highdensity of epoxide groups. Amine groups may be reactive with epoxides,and amine-based molecules may function as hardening agents for epoxyresins. Thus, after applying a dielectric layer at 404 and heat-treatingat 406, covalent bonding between the SAM and the dielectric layer may beestablished. In embodiments, method 400 may enhance adhesion betweencopper and a polymer or dielectric layer with chemical interactions orbonds, rather than mechanical interactions. Chemical interactions areindividually small or weak. However, when provided at sufficientdensity, as may be provided the SAM, chemical interaction may providesubstantial adhesion.

FIG. 5 schematically illustrates a flow diagram for a method 500 offorming a self-assembled monolayer (SAM) on a metal layer (e.g., copper)of a die, in accordance with some embodiments.

At 502, method 500 may include surface cleaning the metal layer. Inembodiments, the surface cleaning may include an acid rinse in anaqueous solution of sulfuric acid to remove oxides from the surface ofthe metal layer.

At 504, method 500 may include immersing the die in a SAM bath. Inembodiments, the SAM bath may include may include an alkane thiol, suchas 11-amino-1-undecanethiol, with a terminal amine group.

At 506, method 500 may include applying a rinse bath to the die. Inembodiments, applying the rinse bath to the die may include immersingthe die in an ethanol bath to remove un-bonded thiol.

Methods 400 and 500 may be performed on a metal layer, such as patternedcopper, as an alternative to “CZ” chemistry. Methods 400 and 500 may beimprovements over copper-roughening chemistry, which may uses many bathsto facilitate oxidative etching.

Various operations are described as multiple discrete operations inturn, in a manner that is most helpful in understanding the claimedsubject matter. However, the order of description should not beconstrued as to imply that these operations are necessarilyorder-dependent. For example, actions of the method 400 may be performedin another suitable order than depicted.

Embodiments of the present disclosure may be implemented into a systemusing any suitable hardware and/or software. FIG. 6 schematicallyillustrates a computing device 600 that may include an IC as describedherein, in accordance with some embodiments. The computing device 600may house a board such as motherboard 602. The motherboard 602 mayinclude a number of components, including but not limited to a processor604 and at least one communication chip 606. The processor 604 may bephysically and electrically coupled to the motherboard 602. In someimplementations, the at least one communication chip 606 may also bephysically and electrically coupled to the motherboard 602. In furtherimplementations, the communication chip 606 may be part of the processor604. In some embodiments, the processor 604 and/or chip 606 may comprisean IC, such as IC 100 or 300 described in reference to FIGS. 1 and 3.

Depending on its applications, computing device 600 may include othercomponents that may or may not be physically and electrically coupled tothe motherboard 602. These other components may include, but are notlimited to, volatile memory (e.g., DRAM), non-volatile memory (e.g.,ROM), flash memory, a graphics processor, a digital signal processor, acrypto processor, a chipset, an antenna, a display, a touchscreendisplay, a touchscreen controller, a battery, an audio codec, a videocodec, a power amplifier, a global positioning system (GPS) device, acompass, a Geiger counter, an accelerometer, a gyroscope, a speaker, acamera, and a mass storage device (such as hard disk drive, compact disk(CD), digital versatile disk (DVD), and so forth). The processor 604 ofthe computing device 600 may be packaged in a stacked IC packageassembly with a memory, as described herein, and/or other components maybe packaged together in a stacked IC package assembly with a memory, asdescribed herein.

The communication chip 606 may enable wireless communications for thetransfer of data to and from the computing device 600. The term“wireless” and its derivatives may be used to describe circuits,devices, systems, methods, techniques, communications channels, etc.,that may communicate data through the use of modulated electromagneticradiation through a non-solid medium. The term does not imply that theassociated devices do not contain any wires, although in someembodiments they might not. The communication chip 606 may implement anyof a number of wireless standards or protocols, including but notlimited to Institute for Electrical and Electronic Engineers (IEEE)standards including Wi-Fi (IEEE 502.11 family), IEEE 502.16 standards(e.g., IEEE 502.16-2005 Amendment), Long-Term Evolution (LTE) projectalong with any amendments, updates, and/or revisions (e.g., advanced LTEproject, ultra mobile broadband (UMB) project (also referred to as“3GPP2”), etc.). IEEE 502.16 compatible BWA networks are generallyreferred to as WiMAX networks, an acronym that stands for WorldwideInteroperability for Microwave Access, which is a certification mark forproducts that pass conformity and interoperability tests for the IEEE502.16 standards. The communication chip 606 may operate in accordancewith a Global System for Mobile Communication (GSM), General PacketRadio Service (GPRS), Universal Mobile Telecommunications System (UMTS),High Speed Packet Access (HSPA), Evolved HSPA (E-HSPA), or LTE network.The communication chip 606 may operate in accordance with Enhanced Datafor GSM Evolution (EDGE), GSM EDGE Radio Access Network (GERAN),Universal Terrestrial Radio Access Network (UTRAN), or Evolved UTRAN(E-UTRAN). The communication chip 606 may operate in accordance withCode Division Multiple Access (CDMA), Time Division Multiple Access(TDMA), Digital Enhanced Cordless Telecommunications (DECT),Evolution-Data Optimized (EV-DO), derivatives thereof, as well as anyother wireless protocols that are designated as 3G, 4G, 5G, and beyond.The communication chip 606 may operate in accordance with other wirelessprotocols in other embodiments.

The computing device 600 may include a plurality of communication chips606. For instance, a first communication chip 606 may be dedicated toshorter range wireless communications such as Wi-Fi and Bluetooth and asecond communication chip 606 may be dedicated to longer range wirelesscommunications such as GPS, EDGE, GPRS, CDMA, WiMAX, LTE, Ev-DO, andothers.

In various implementations, the computing device 600 may be a laptop, anetbook, a notebook, an ultrabook, a smartphone, a tablet, a personaldigital assistant (PDA), an ultra mobile PC, a mobile phone, a desktopcomputer, a server, a printer, a scanner, a monitor, a set-top box, anentertainment control unit, a digital camera, a portable music player,or a digital video recorder. In an embodiment, the computing device 600may be a mobile computing device. In further implementations, thecomputing device 600 may be any other electronic device that processesdata.

Examples

Some non-limiting examples are provided below.

Example 1 may include a method of fabricating an integrated circuit(IC), the method comprising: forming on at least one of a metal layer ora polymer layer of a die a surface layer that includes anadhesion-functional group; and applying to the surface layer a nextlayer to adhere to the surface layer with the adhesion-functional group.

Example 2 may include the method of example 1, wherein the at least oneof the metal layer or the polymer layer is a polymer layer and formingthe surface layer includes copolymerizing on the polymer layer a polarmonomer that includes the adhesion-functional group.

Example 3 may include the method of example 2, wherein forming thesurface layer further comprises: dispensing on the polymer layer asolution that includes a photoinitiator and the polar monomer with theadhesion-functional group; and exposing the solution to light to formthe surface layer on the polymer layer.

Example 4 may include the method of example 3 wherein exposing thesolution to light copolymerizes the polar monomer on the polymer layer.

Example 5 may include the method of any of examples 2-4 wherein theadhesion-functional group includes an amine group.

Example 6 may include the method of example 5 wherein the next layerincludes silica.

Example 7 may include the method of any of examples 2-4 wherein theadhesion-functional group includes a cyano group.

Example 8 may include the method of example 7 wherein the next layerincludes a metal.

Example 9 may include the method of any of examples 2-4 wherein theadhesion-functional group includes a hydroxyl group.

Example 10 may include the method of any examples 2-4 wherein the nextlayer includes a second polymer layer.

Example 11 may include the method of example 2 wherein the polar monomerfurther includes a second adhesion-functional group.

Example 12 may include the method of example 1, wherein the at least oneof the metal layer or the polymer layer is a metal layer and forming thesurface layer includes forming on the metal layer a self-assembledmonolayer that includes amine group terminations.

Example 13 may include the method of example 12, wherein applying thenext layer further comprises: forming the next layer as a dielectriclayer; and heat-treating the die to affix the dielectric layer to themetal layer.

Example 14 may include the method of any of examples 12-13 whereinforming the self-assembled monolayer includes applying to the metallayer an ethanolic solution that includes an alkane thiol with aterminal amine group.

Example 15 may include the method of example 14 wherein applying thesolution to the metal layer includes immersing the die in the solution.

Example 16 may include an integrated circuit (IC), comprising: a polymerlayer of a first monomer on a die; a polymer surface layer with a polarmonomer that is copolymerized on the polymer layer, wherein the polarmonomer includes a functional group and the polymer layer is free fromthe functional group.

Example 17 may include the IC of example 16 further comprising asubsequent layer applied to the polymer surface layer with adhesionfunctional by the functional group.

Example 18 may include the IC of example 16 wherein the functional groupincludes an amine group.

Example 19 may include the IC of example 16 wherein the functional groupincludes a cyano group.

Example 20 may include the IC of example 19 wherein the next layerincludes a metal.

Example 21 may include the IC of example 16 wherein the functional groupincludes a hydroxyl group.

Example 22 may include the IC of example 18 in which the next layerincludes silica.

Example 23 may include the IC of example 21 in which the next layerincludes a solder resist.

Example 24 may include the IC of example 16 in which the next layerincludes a second polymer layer.

Example 25 may include the IC of example 24 in which the second polymerlayer embeds the die in an IC package assembly.

Example 26 may include the IC of example 24 in which the second polymerlayer includes an underfill material.

Example 27 may include an integrated circuit (IC), comprising: a diewith multiple layers that include a metal layer; a surface layer on themetal layer, wherein the surface layer includes amine groupterminations; and a heat-treated dielectric layer on the surface layer.

Example 28 may include the IC of example 27 wherein the surface layerincludes a self-assembled monolayer.

Example 29 may include the IC of example 28 wherein the self-assembledmonolayer is thiol-based.

Example 30 may include a method of fabricating an integrated circuit(IC), the method comprising: providing a die with a polymer layer;dispensing on the polymer layer a solution that includes a polar monomerand a photoinitiator; exposing the solution to light to form on thepolymer layer an adhesion-receptive polymer surface; and applying a nextlayer to the adhesion-receptive polymer surface.

Example 31 may include the method of example 30 in which exposing thesolution to light copolymerizes the polar monomer on the polymer layerto form the adhesion-receptive polymer surface.

Example 32 may include the method of example 30 in which the polarmonomer includes an amine group.

Example 33 may include the method of example 32 in which the next layerincludes silica.

Example 34 may include the method of example 30 in which the polarmonomer includes a cyano group.

Example 35 may include the method of example 34 in which the next layerincludes a metal.

Example 36 may include the method of example 30 in which the polarmonomer includes a hydroxyl group.

Example 37 may include the method of example 36 in which the next layerincludes a solder resist.

Example 38 may include the method of example 30 in which the next layerincludes a second polymer layer.

Example 39 may include the method of example 30 in which the lightincludes ultra-violet light.

Example 40 may include a method of fabricating an integrated circuit(IC), the method comprising: providing a die with a first metal layer;forming on the metal layer a self-assembled monolayer that includesamine group terminations; forming a dielectric layer on theself-assembled monolayer; and heat-treating the die.

Example 41 may include the method of example 40 in which forming theself-assembled monolayer includes applying to the first metal layer asolution that includes an alkane thiol with a terminal amine group.

Example 42 may include the method of example 41 in which the solution isethanolic.

Example 43 may include the method of any of examples 41-42 in whichapplying the solution to the first metal layer includes immersing thedie in the solution.

Example 44 may include the method of example 40 in which forming adielectric layer on the self-assembled monolayer includes applying adielectric epoxy resin.

Example 45 may include a method of fabricating an integrated circuit(IC), the method comprising: providing a die with a first metal layer;applying to the first metal layer an ethanolic solution that includes analkane thiol with a terminal amine group to form a surface layer withamine group terminations; applying a dielectric layer on the surfacelayer; and heat-treating the die.

Example 46 may include the method of example 45 in which applying theethanolic solution to the first metal layer includes immersing the diein the ethanolic solution.

Example 47 may include the method of example 45 in which applying thedielectric layer on the surface layer includes applying a dielectricepoxy resin.

The above description of illustrated implementations, including what isdescribed in the Abstract, is not intended to be exhaustive or to limitthe embodiments of the present disclosure to the precise formsdisclosed. While specific implementations and examples are describedherein for illustrative purposes, various equivalent modifications arepossible within the scope of the present disclosure, as those skilled inthe relevant art will recognize.

These modifications may be made to embodiments of the present disclosurein light of the above detailed description. The terms used in thefollowing claims should not be construed to limit various embodiments ofthe present disclosure to the specific implementations disclosed in thespecification and the claims. Rather, the scope is to be determinedentirely by the following claims, which are to be construed inaccordance with established doctrines of claim interpretation.

What is claimed is:
 1. A method of fabricating an integrated circuit(IC), the method comprising: forming on at least one of a metal layer ora polymer layer of a die a surface layer that includes anadhesion-functional group; and applying to the surface layer a nextlayer to adhere to the surface layer with the adhesion-functional group.2. The method of claim 1, wherein the at least one of the metal layer orthe polymer layer is a polymer layer and forming the surface layerincludes copolymerizing on the polymer layer a polar monomer thatincludes the adhesion-functional group.
 3. The method of claim 2,wherein forming the surface layer further comprises: dispensing on thepolymer layer a solution that includes a photoinitiator and the polarmonomer with the adhesion-functional group; and exposing the solution tolight to form the surface layer on the polymer layer.
 4. The method ofclaim 3 wherein exposing the solution to light copolymerizes the polarmonomer on the polymer layer.
 5. The method of claim 2 wherein theadhesion-functional group includes an amine group.
 6. The method ofclaim 5 wherein the next layer includes silica.
 7. The method of claim 2wherein the adhesion-functional group includes a cyano group.
 8. Themethod of claim 7 wherein the next layer includes a metal.
 9. The methodof claim 2 wherein the adhesion-functional group includes a hydroxylgroup.
 10. The method of claim 2 wherein the next layer includes asecond polymer layer.
 11. The method of claim 2 wherein the polarmonomer further includes a second adhesion-functional group.
 12. Themethod of claim 1, wherein the at least one of the metal layer or thepolymer layer is a metal layer and forming the surface layer includesforming on the metal layer a self-assembled monolayer that includesamine group terminations.
 13. The method of claim 12, wherein applyingthe next layer further comprises: forming the next layer as a dielectriclayer; and heat-treating the die to affix the dielectric layer to themetal layer.
 14. The method of claim 12 wherein forming theself-assembled monolayer includes applying to the metal layer anethanolic solution that includes an alkane thiol with a terminal aminegroup.
 15. The method of claim 14 wherein applying the solution to themetal layer includes immersing the die in the solution.
 16. Anintegrated circuit (IC), comprising: a polymer layer of a first monomeron a die; a polymer surface layer with a polar monomer that iscopolymerized on the polymer layer, wherein the polar monomer includes afunctional group and the polymer layer is free from the functionalgroup.
 17. The IC of claim 16 further comprising a subsequent layerapplied to the polymer surface layer with adhesion functional by thefunctional group.
 18. The IC of claim 16 wherein the functional groupincludes an amine group.
 19. The IC of claim 16 wherein the functionalgroup includes a cyano group.
 20. The IC of claim 19 wherein the nextlayer includes a metal.
 21. The IC of claim 16 wherein the functionalgroup includes a hydroxyl group.
 22. An integrated circuit (IC),comprising: a die with multiple layers that include a metal layer; asurface layer on the metal layer, wherein the surface layer includesamine group terminations; and a heat-treated dielectric layer on thesurface layer.
 23. The IC of claim 22 wherein the surface layer includesa self-assembled monolayer.
 24. The IC of claim 23 wherein theself-assembled monolayer is thiol-based.